Control device



y 1953 E. J. DILLMAN 2,638,121

CONTROL DEVICE Filed May 11, 1948 4 Sheets-Sheet l MKM 4L1 ATTORNEY May12, 1953 E. J. DILLMAN 2,638,121

CONTROL DEVICE Filed May 11, 1948 4 Sheets-Sheet 5 IN VEN TOR.

Mi M

I 2 W (M FIG 5 AL ATTORNEY y 53 E. J. DILLMAN 2,638,121

CONTROL DEVICE Filed y 11, 8 4 Sheets-Sheet 4 IN V EN TOR.

Mg. bimam,

M ATTORNEY Patented May 12, 1953 CONTROL DEVICE Earnest J., Dillrnan,Detroit, Mich, assignor to Detroit Controls Corporation, a corporationof Michigan Application May 11, 1948, Serial No. 26,429

8 Claims.

This invention relates to new and useful immovements in liquid fuelburner systems and m re p rticularly to control devices therefor,

One of the objects of this invention is to provide a control systemhaving a plurality of liquid .fuel burners having a. common supply offuel.

An th r o j t is to provide a control d v ce for selectively directingthe new of iquid f el o each of a plurality of l qu d fuel burners.

Another object is to provide a. liquid flow controlling device having apressure determining means therein and h ving a means f r lead ng fuelback to the source of supply at p es ur s below that determined by thepressure determining means.

Another object is to provide a control device having a means forselectively directing the flow of fuel to two burners and fortransferring control between two control systems which control theoperation 01' said burners.

Another object is to provide a novel valve and switch combination in aliquid fuel burner control device,

Another object is to provide a control device for a two burner controlsystem by which the fuel 'supply is discontinued to one burner beforethe control valve switches the supply from that burner to the other.

Another object is to provide a novel means of adjustment for anoperating lever in a control device.

Another object is to provide a control device having a novel means forinducing a snap or quick action of an operating member.

Other objects will become apparent from time to time throughout thespecification and claims as hereinafter related.

This invention consists of the new and im.. proved control system andcontrol device therefor and of the combination and cooperation of thepartsthereof which will be described more fully hereinafter and thenovelty of which will be particularly pointed ,out and distinctlyclaimed.

In the accompanying drawings to be taken as part of the specification,there is clearly and fully illustrated one preferred embodiment of thisinvention in which drawings:

Figure 1 is a view in front elevation of a con trol device embodyingthis invention,

Fig. 2 is a op Plan view of this control device,

Fig. 8 is a sectional view taken on the section line 3-.--3 of Fig, 2 ofthis control device and which shows the construction and relation of thecontrol valves to the various outlet passageways,

Fig, 4 is a sectional view taken on the section line "4 of Fig. 2, andwhich shows the thermostatic means for operating this device.

Fi 5 is a sectional view taken on the line 5-5 of Fig. 4 and which showsthe liquid inlet to the control device and the actuating lever therefor,

Fi 6. is a sectional vi w ak o the se t n li e 6* f g! ig. 7 is a planview of this control device with the cover member removed an shown nPartia section to show the means for adjusting the Sn il acting device,

Fig. 8 is a bottom plan view of the cover member of this device whenremoved, and

Fig, 9 is a diagrammatic view of this control device installed in acontrol system for controlling a pair of liquid fuel burners.

Referring to the drawings by characters of reference, there is a controldevice I comprising a liquid fuel receiving casing 2 having an inletpassageway 3 and a p ir f outlet passag s. 5- he cas ng 2 has a cover mer 6 of aneleetric insulating material which is secured to and seals theopen top of the casin the cover membe 5 being secured to the casing 2On. a f ange 1 Whiflh extends around t e o en top f the casing- "Ihe eis a va e e n memb 8 h ch is secured t the c er mem r .6 alone one nd n9ion th r f. Th va ve casin 8 has a pai o pr e porti s 9, 10 w h e d,through a pa r f ap rtu s n the c er em er 5. The projecting portions 9,1.0 are externally screwthreaded and are secured to the cover member 8by a, pair of nuts I I, I2. The projecting portions 9, ill have boresI3, [4 therein which open into smaller bores I5, l6 forming valve portsand cooperating with the bores 13, I4 to form valve seats. There are apair of valve members ll, [8 which fit slidably in the bores l3, l4 andwhich function to control how of liquid fuel therethrough. The valvemembers ll, 18 are of polygonal cross-section to permit flow of fuel tothe valve ports l5, It. The valve casing 8 has a pair of cylindricalcavities at each end thereof in which are screw-threadedly secured apair of plug members 19, 20. The bores or ducts l5, 16 open respectivelyinto passages 2! 22 which communicate at one end thereof through bleedorifices 23, 24 into a bleed or auxiliary outlet passageway 25. Theother ends of the passages 2t, 22 communicate with annular cavities 26,2'! respectively which are closed by resilient elastic diaphragms 28, 29respectively of a pair of diaphragm type check valves. The plug membersIt, 20 in the valve casing 8 are each hollow and have hollow operatingpistons 30, 3t therein which are held compressively against thediaphragms 28, 29 by helical springs 32, 33. lhe diaphragms 28, 29 whichare clamped in position by the plug memhere 19, 2 respectively, are heldcompressively closing a pair of passages 34, 35 which open into theoutlet passages 4, 5. Secured to the under surface of the cover member 6is a bracket 36 which supports the fulcrum pin 31 of an operating lever38 which controls the opening and closing movement of the valves ll, 18,The operating lever 38 fits at its opposite ends into lostmotion slots39, 40 in the valves |'i, I8. The operating lever 38 is adjustablysecured to a lever supporting member 4| which is formed of sheet metalhaving a plane central portion and downturned projections or ears 42 ateach end through which extends the pivot pin 37. There is a supportingmember 43 of an electric insulating material which is secured to andcarried by the lever supporting member 4|. The operating lever 33 has agrooved central portion which rides on the pivot pin and has a pair ofapertures on opposite sides of the fulcrum pin 31 through which extend apair of bolts 44, 45 which are adjustably secured in the supportingmembers 4|, 43. There is a helical spring 46 surrounding each of thebolts 44, 45 which is positioned between the lever supporting member 4|and the lever 33 and hich holds the lever 38 compressively against theheads of the bolts 44, 45. It is obvious then that the lever 38 can berotatably adjusted relative to the supporting member 4| by proper inwardand outward adjustment of the bolts 44, 45 thereby permitting adjustmentof the amount of opening of the control valves I1, I 8.

The cover member 5 of the casing 2 carries four pairs of electricalcontact terminals or binding posts 41 which are connected to fixedcontacts 48 of an electr c switch. There are four pairs of movableswitch contacts 49 which are carried by the supporting member 43 on thelever supporting member 4| and which are connected thereto by resilientarms 50. It is seen then that upon rocking movement of the lever in onedirection one of the valves is opened and one closed and two pairs ofmovable contacts are closed against their respective fixed contactswhile two pairs of movable contacts are opened. The lever supportingmember 4| has a downturned and bifurcated projectin portion 5| at theend opposite the valves. There is a lever 52 which is pivoted on abracket 53 and which extends between the prongs of the bifurcatedprojection 5|. The lever 52 when moved engages one or the other of theprongs of the bifurcated projection 5| and causes the lever and electriccontacts to be rocked. Positioned between flames on the lever 52 thereis a pivoted member 54 which has a pair of annular shoulders out intothe op osite faces thereof. The casing 2 has a pair of apertures 55, 55which are oppositely alined in line with the pivoted annular member 54.There is a plug member 5'! which is screw-threadedly secured in theaperture 55 and which has an adjustment screw 53 extending lonitudinally there through into the chamber enclosed by the easing 2. Theadjustment screw 58 is enclosed by a cover member 59 which isscrew-threadedly secured to the exterior of the plug member 51.

The adjustment screw 58 has a small project ng portion 6|! which proects into a cylindrical cavity in a spring supporting member 6|. Thesupporting member 6| has an annular flan e 82 thereon against hich bearsone end of a helical spring 53, the other end of which bears a ainst oneannular shoulder of the pivoted member 54. At the opposite side of thecasin 2 t ere is a plug member 64 which is screw-threade lly secured inthe aperture 55. The lu member 64 has a bore 65 extendin substantiallyalong the lon itudinal axis thereof, w ich bore is of reduced size in te inner end portion thereof. There is a piston member 6 w ich sli ablyfi s the reduced end portion of the bore 65 and which extends into thechamber enclosed by the casing 2 and which has an annular shoulder uponwhich seats a spring supporting member 5? having a flange 58. There is ahelical spring 69 which is compressively positioned between the flangeportion 58 of the member 57 and the other annular shoulder of thepivoted member 54, the springs 69, 53 being oppositely alined.Positioned in the enlarged portion of the bore 55 and extendingpartially into the reduced portion is an elastic plug member of aresiliently elastic material such as a rubber or synthetic rubber. Thebore 65 at its enlarged end opens into a cylindrical recess or cavity Hwhich is closed by a cover member I2. The enlarged open end of the bore65 is closed off from the cavity H by a flexible diaphragm l3 of aresiliently elastic material such as rubber or synthetic rubber, Thediaphragm I3- is secured against vthe end wall of the recess H by thecover member 12 and abuts the plug member 10, the cover member |2 beingheld rigidly in position by an inturned annular flange M. The covermember 72 has .an aperture therein opening into the cavity H and inwhich is sealed a tube or conduit 15 which leads to a thermostaticelement 15. The bulb element 16 contains an expansible fluid vwhich isresponsive to temperature and operable to transmit an expansive force tothe cavity (I which is expanded thereby and its force transmittedthrough the diaphragm i3 and plug 70 to move the piston 65. Theaforementioned movement of the piston 55 is transmitted through thespring 69 to the lever 52 for operating the control lever 38. The lever52 has a projecting portion 11 at its free end portion which extendsinto a cylindrical recess iii in the bottom wall of the casing 2, thewalls of the cylindrical recess !8 functionins as limit stops for thelever 52. There is another lever 75 which is pivoted on a bracket on theside wall of the casing 2 and which has an adjustment screw or bolt 8|at its free end port on. There is a threaded member 82 screwthreadedlysecured on the bolt 8| and to which is secured one end of a helicalspring 83. The other end of the spring 83 is secured to a screw threadedmember 84 on an adjustment bolt 85 which extends through an aperture 86in the end wall of the casing 2, the aperture 86 having an enlargedouter end portion which is closed by a bolt-like closure member 81. Thelever 52 has an inturned flange portion 88 on its free'end against whichis pivoted one end of a pivoted mem er 89, the other end of which ispivoted against the midortion of the lever 19. The pivoted member 89 iscompressively held by'the force of the spring 83 between the lever 19and the flan e portion 88 of the lever 52 and is operable to transmit abiasing thrust therebetween. In operation this control device functionsas follows:

Liquid fuel is supplied to the chamber enclosed by the casing 2 throughthe inlet 3 under press re by a pump 90 (shown diagrammatically in Fi9). This fuel is discharged through the open val e M under pressure andthrough the passages Ni, 2.2 to the annular cavity 21 which is closed bythe diaphragm check valve 29. The check valve 29 is set to open at apredetermined pressure of say 60 p. s. i. at which pressure the dia hram 29 forces the piston 23 into the cylindrical cavity in the plug member24 against the sprint, .As the diaphragm 29 is moved, the o ening to thepassage 35 is opened to permit flow t rough that passage into the outletpassage 5, which leads to one of the burners controlled by this device.When the heat output in the one burner has reached a sufiicient amountthe thermostatic bulb 16 which is responsiveto said heat output willtransmit fluid expansion to the chamber H and an expansive force throughthe diaphragm and plug member as heretofore described to the piston 66which acts through the sprin 69 to move the lever 52 against the forceof the spring 63, The amount of force required to move the lever 52 maybe adjusted by the adjustment screw 58 which determines the compressiveforce exerted by the spring 63 which adjustment will determined thetemperature of the bulb element 16 which is required to cause the lever52 to be moved. As the lever 52 is moved, the pivoted member 89 pivotstherewith and causes the lever 19 to move outward thus tensioning thespring 83. When the lever 52 has moved to an over-center position thespring 83 acting through the lever!!! and the pivoted member 89 willcause the lever 52 to move through the remainder of its travel with asnap action. The movement of the lever 52 with a snap action will causeit to engage one of the prongs of the bifurcated projection 5| and torock the lever 38 and electrical. contact arms with a snap action. Thereis a fraction spring 9| which is positioned between the end portion 51of the lever supporting structure ll and the supporting bracket 35 whichfunctions to hold the lever supporting member 4] in any predeterminedposition when cracking force is not being applied thereto. This springbears against two raised or embossed portions of the projecting port on5] and will hold the lever supporting member 4! at one of the twoextremes of movement with the valve tacts. The lever 38 which operatesthe valves H, 18 extends into the slotted end portions .35, ll ofthese'valves and is operable to provide a lost motion in the opening ofthese valves. When the lever begins its movement it must move from oneside of'one of the slots 39 or 4D to the other side of the slot beforethe valve can begin to open. The-oil pressure at which the burner isoperated is normally about 90 p. s. i. and: this pressure is sufiicientto resist opening of the valve which is closed until the operatingpressure drops to a small value of say, p. s. i. The lost motion featurein the valves and the pressure 'which holds the valve I! closed isoperable-to .hold the valve closed while permitting the switch ,contactsto open. With the switch contacts open the pump is deenergized and whenthe pressure in the valve casing drops to the lower pressure (10 p. s.i.) the valves and switch contacts are permitted to move through theremainder of their travel to re-establish the pump and burner circuitand to open and close the respective valves as required. The switchcontacts which are fopened and closed in sequential synchronization withthe opening and closing of the valves are operable to switch between twosets of control circuits which control the operation of the pump 90which'supplies fuel to the open one of the valves. The central outletpassageway 25 or bleed passageway communicates through reduced -o pen'mgor orifices 13, 24 with the passages 2|,

22 leading from the outlet l5, Hi from thevalvo I1, 18. During periodswhen only one of the burners supplied by this control device is inoperation the switching of the valve and switch contacts will deenergizethe pump but the inertia of the pump will cause a fuel pressure tocontinue for a short time and fuel could be supplied through the openvalve to the inactive burner. With the bleed outlet and lost motionvalve opening described, this shore supply of fuel through the inactiveburner valve portwould be so reduced in pressure as to be insufficientto open the check valve and would bebled through the orifices anddischarged through the bleed outlet 25 and a connecting conduit backto-the source of fuel supply..

In Fig. 9 the control device heretofore described is shown installed ina control system for controlling flow of fuel to a household heatingburner and a domestic water heating burner. In this system there is afuel sump 92 for supplying fuel to a conduit 93 leading to the pump 90,the pump supplying fuel through the conduit 94 to the inlet 3 of thecontrol device. From the control device 1 one conduit 95 leads to ahouse heating burner 96 and another conduit 91 leads to a domestic waterheating burner 98. The burners 95, 93 are supplied with air by a commonmotor driven fan 83 by which motor the pump 96 is driven. There is anair duct I00 leading from the fan 58 to the burner 96 and a branch ductI 0! leading to the burner 98. The stack I82 from the burner 98 isconnected to the stack H33 of the house heating burner 96. Thethermostatic bulb element 15 is responsive to'the temperature of thewater supply and is inserted in the water heating jacket 04 surroundingthe burner 88. The electric control systemfor the control of the burners96, 98 is as follows:

There is a main power source I05 from-which a pair of conductors IE5,I07 run to 'the'terminals I08, I09 of an electric primary control deviceH0. From the terminal III on the control device no a conductor H2runs tothe terminal N3 of the motor of the fan 99 which is'connected to themain power source H35 by a'c'onductor H4 leading from the other fanmotorterniinal H5. The terminals H38, I 69 of the control device H8 areconnected to the primary H6 of a transformer i H. The transformer i I!has a secondary coil 1 l B which has three terminal connections thereon.From one of the secondary terminals H9 a conductor i20 runs to athermostatio-warp switch Hi, the contacts |22,'l-23 of which arenormally closed. From the fixed contact l23 of the warp switch I21 aconductor I24 leads to a terminal of the control device Hi3. From theterminal I26 of the transformer secondary i 18 a conductor runs to aheater coil I21 for the thermal warp switch 12!, the heater coil i2!being connected by a conductor I28 to a terminal 12!! on the controldevice! Hl. From the terminal of the transformer secondary I18 aconductor l3! leads to a movable contact 32 of a bicole relay switch[33. The fixed contact 134 of the relay switch 133 is connected to therelay coil which is in turn connected by condoctor 13%; to the terminalI31 of the control olevice H8. The fixed relay contact 134 is alsoconnected by a conductor I38 to a terminal 1390f the control device Hitand by conductors H0, 14! and the closed. contacts 142, .143 of athermostatic stack switch I44 to the control device terminal 145. Thereis a iumper H5 which'leads from the transformer primary H6 to a secondmovable contact I41 cooperable with a fixed cons tact I48 of the relayswitch I33. The fixed contact I46 0f the relay switch I33 is connectedby a conductor I49 to the terminal III. On the control device -I thereare a plurality of pairs of fixed switch contacts I53 and I5I, I52 andI53, I54 and I55, I56 and I51 with which cooperate the movable pairs ofcontacts 49. There is a conductor I58 running from the terminal I25 ofthe control device III) to the fixed contact I52 of the control deviceI. The terminal I31 of the control device H is connected by a conductorI59 to the contact I53, which contact is connected by a conductor I60 tothe terminal I6I of a room thermostat I62. The thermostat terminal I6Iis connected to a bimetal element I63 which carries a movable contactI64 and is also connected to a compensating heater coil I65 which is inturn connected by a conductor I66 to the contact I55 of the controldevice I. The fixed contact I61 which cooperates with the movablecontact I64 is connected by a conductor I68 to the contact I51 of thecontrol device I. There is a jumper wire I69 connecting the contacts I52and I56 of the control device I and a similar jumper I19 connecting thecontacts II, I55. From the contact -I5I a conductor I1I leads to theterminal I29 of the control device H0 and a conductor I12 similarlyconnects the contact I 54 to the terminal I45. From the terminal I50 aconductor I13 leads to the fixed contact I14 of a thermostatic stackswitch I15, the other contact of which (I16) is normally closedthereagainst. From the movable contact I16 of the thermostatic stackswitch I a conductor I11 leads to the terminal I 39 of the controldevice I III.

In operation this control system functions as follows:

The control device I is shown diagrammatically and corresponds to theposition shown in the various views of the device itself. In theposition shown, the hot water tank I64 has cooled and the movable pairsof contacts 49 have closed against the fixed pairs of contacts I50 andI5I, I52 and I53 to complete a control circuit for supplying fuel to thehot water heater. In this position (see Fig. 3) the valve I8 of thecontrol device is open and operable to permit passage of fuel to the hotwater heater 98 through conduit 91-. A circuit is completed from themain power source I05 to conductors I06, I61 to the primary H6 of thetransformer II1. With the transformer II1 energized a circuit iscompleted from the transformersecondary terminal H9 by way of conductorI20, closed contacts I22, I23 of the warp switch I2I and conductor I24to the control device terminal I25. From the terminal I25 the circuitruns through conductor I53 to the contact I 52 of the control device I,through the closed switch contacts to the contact I53 and thence byconductor I59 to the terminal I31 of the control device -I I 0. From theterminal I31 the circuit runs by conductor I3 6 to the coil I35 of therelay I33 and thence by conductor I 38 to the terminal I 39. From theterminal I39 the circuit runs by conductor I11 through the closedcontacts I14, I16

of the stack switch I15 and by conductor I13 to contact I of the controldevice I. From contact I50 the circuit is completed through the closedcontacts 49 to contact I5I and thence by conductor I1I to terminal I29of the control device IIO. From the terminal I29 the circuit iscompleted by conductor I28 and the heater coil I21 to the terminal I26on the transformer sec-- 'ondary I I8. It is thus seen that a circuit iscom- 8 pleted through the coilof the relay switch I33 to the closedcontacts of the timer warp switch I2 5 and through the closed contactsof the stack switch I15. When the relay switch I33 is energized the.movable contacts I32, I41 are closed against the fixed contacts I 34,I48. When the contacts I41, I48 are closed the circuit is completed fromthe main power source by conductor I06 and conductor I46, the closedcontacts I41, I48 and conductor M9 to the terminal III of the controldevice III]. From the control terminal I I I the circuit runs byconductor I I2 to the motor of the fan 99 and by conductor H4 back tothe main power source. It is then seen that upon energization of therelay switch I33 the circuit is completed through the fan motor foroperation of the fan- 99 and for operation of the pump which suppliesfuel through the open valve I8 and outlet 5 in the control device I tothe hot water burner 96 through the conduit 91. Simultaneous with theestablishment of the circuit for energization of the fan and pump acircuit is completed through the closed contacts I32, I34 of the relayswitch from the terminal I30 of the transformer secondary H8. Thiscircuit is a holding circuit which runs from the terminal I I8 byconductori3i, closed contacts I32, I34, the relay coil I35, conductorI36 to the terminal I31 of the control device III). From the terminalI31 the circuit runs by conductor I59, contacts I52, I53, conductor I59,terminal I25, conductor I24, the closed contacts I23, I22 of the warpswitch I2I and conductor I20 back to the terminal II9 of the transformersecondary II6. Since the initial energizing circuit for the relay switchI33 was established through the heater I21 for the warp switch I2I andthe stack switch I15, it will be obvious that unless the initial circuitis opened Within a short predetermined time the heater I21 will causethe contacts I22, I23 of the warp switch I2I to open thus deenergizingthe relay I33 and stopping the fan and pump. The stack switch I15 has athermostatic element positioned in the stack from the hot water burnerand upon occurrence of flame in the hot water burner the therswitch I15thus breaking the circuit through the heater coil I21 of the warp switchI2I and deenergizing the initial circuit for energizing the relay I33.The burner 98 will then continue to heat until the domestic hot watersupply is heated to the desired temperature at which time thethermostatic power element bulb 1 6 will have been heated sufficientlyto transmit power to. the control device I and cause the levers to movethus closing the valve I8 and opening the valve I1 and opening andclosing the corresponding switch contacts. As was described heretoforethe lost motion in the opening of the valve I1 is such that the circuitthrough the switch contacts across the terminals I59 and I5I, I52 andI53 in the control device I are broken and the pump 90 ole-energizedprior to the opening of the valve I1 so that fuel will not be ejectedthrough the valve I1 should the household burner 96 not require heat.With the valve I1 open and the switch contacts I54 and I55, I 56 and I51closed which occurs sequentially to the opening of contacts I50 and I5I,I52 and I53 the control device I is now in position to supply fuel tothe household burner 96 as required. As described before, thetransformer II1 of the control device H0 is en ergized at all times fromthe main power source I95. With the switch contacts moved-as describedin the control device i a new circuit will now be completed from theterminal H9 of the transformer secondary IIB through the contacts I22,I23 of the warp switch I2i and by terminal I25 and conductor I58 to thecontact I52 of the control device I. From the contact I52 the circuitruns by the jumper 569 to and through the closed contacts 56, I51 and byconductor I68 to the fixed contact Isl of the room thermostat H52. Ifthe room thermostat I52 is demanding heat and the contact IE4 is closedagainst the contact It? the circuit will be completed through thebimetal I53 I60 to contact I53 of the control device 1. From the contact553 conductors I59, 136 run to the coil I35 of the relay switch I33.From the relay coil I53 a circuit runs by conductor I49 to the closedcontacts I42, 143 of the household burner stack switch I 35 and byconductors I4I, I12 to the contact I54 of the control device I. Fromthevcontact I55 the circuit runs through contact I55, the conductor N55to the compensating heater 355 on the room thermostat H52. A branchcir-v cult runs from a contact I55 by jumper to contact i5l which isconnected by conductor ill to a. terminal 29 on the control device I I0.The circuit is then completed from. the terminal IZQ by conductor I28and the warp switch heater l2! to the terminal I26 on the transformersecondary IIS. From this circuit it is seen that the circuit iscompleted through the room thermostat H52 as heat is called for andthrough the closed contacts of the stack switch I at, the relay coilI35, and through the contacts of the warp switch heater I21. When therelay switch I33 is energized and the contacts I41 and I48 closed, thecircuit is completed as previously described through the fan motor forenergizing the fan 99 and the pump 90 for supplying of fuel to thehousehold burner through the open valve I! and outlet 4 by conduit 95.Upon closing of the contacts I32, 13s of the relay switch I33, a circuitis established from the transformer secondary terminal i150 through theclosed. contacts F32, I 34, the relay coil 35,. conductors 136, 59, ISOto the room thermostat 152. From. the room thermostat i 32 the circuitruns by conductor i i-8, contacts I56, 151, jumper Ills, conductors I58,ill, the closed contacts I22, 123 of the warp switch. I21 and conductorI20 leading back to the transformer secondary terminal I19. As wasdescribed before, the initial circuit for the energizetion oi the relaycoil 135 runs through the closed contacts of both the stack switch 544-:and the warp switch 12!, and the warp switch heater I21;

Since the holding. circuit for the relay coil 35 through the closedcontacts L32, [34 also runs through the closed contacts of the warpswitch l2I it is necessary that the initial relay cofl energizingcircuit be broken within a short predetermined time or the opening ofthe warp switch'contacts I22, $23 will tie-energize both the initialand. the holding, circuits of the relay I33 and will stop the fan andpump. As was described for the control system of the water heater, thestaclr switch I'M performs a similar function to the stack switch I inthat it is responsiveto the occurrence of flame in. the household burnerUpon occurrence of flame in the household burner 96 the stack switchcontacts [42, M3 will open thus tie-energizing the circuit through thewarp switch heater I21 and leaving the holding circuit to the relay coilI35 in control of theoperation of the fan and pump. As was describedheretofore the holding circuit and terminal IGI, by conductor for therelay coil I includes the switch contacts of the control device I andthe contacts I64, I67 of the thermostat I62 so that if the roomthermostat should be satisfied the relay coil will be ale-energized orif the househould water supply should cool a sufiicient amount that theswitches of the control device I are moved the household heating circuitwould similarly be broken. It should be noted that the check valves cs,29' and the bleed outlet 25 as described heretoforepermit the bleedingof fuel back to the sump d2 by a conduit 93 This bleed arrangementtogether with the delayed opening of the valve as pre viously describedprevents fuel from being discharged into the household burner 96 whenthe control device 6 switches over from the water heating burner if theroom thermostat Hi2 is not calling for heat and causes fuel pressurecreated by the inertia of the pump to be relieved through the bleedoutlet 25 back to the sump 92 From the description heretofore given itis seen that there is provided a pair of circuit networks forcontrolling a two burner system whfleby the demand of heat by thedomestic water heating system will switch the control device I to aposi-' tion for supplying fuel to the water heating burner 98 and switchto a control system for the burner 98. Similarly, when the water supplyis adequately heated the control devieewill switch fuel back to thehouse heating burner 95 and place its control system in control.

Having thus described the invention, what is claimed and is desired tobe secured by Letters Patent of the United States is:

l. A control device comprising a casing having a fluid. inlet and a pairof fluid outlets, a pair of valves for controlling ii'uid flow throughsaid outlets, means for opening and closing said valves,- ineanspositioned in each of said outlets and operable to determine thepressure of fluid discharging therethrough, an auxiliary outlet fromsaid casing, and means for bleeding fluid from said first-named outletsto saidauxiliary outlet at points between said valves and said pressuredetermining means.

2. A control device comprising a casing having a fluid inlet and a pairof. fluid outlets, a pair of valves for controlling fluid now throughsaid outlets, means for opening and closing said valves, meanspositioned in each'of said outlets and operable to determine thepressure of fluid discharging therethrough, an auxiliary outlet' fromsaid casing, and a pair of fixed and cont-inually open orifices openingfrom. said firstnamed outlets into said auxiliary outlet and open ableto bleed fluid from said first-named outlets to said. auxiliary outletat points between said valves and said pressure determining means.

3. A control device comprising a casing enclos ing a chamber, a fluidinlet passageway to said chamber, a pair of outlet passageways and ableed passageway in said casing, a pair of ducts leading from. saidchamber to said outlet passage" ways a pair of valves for controllingfluid flow through said ducts, a roclrable lever operatively connectedto said valves and operable upon rock-j ing movement to open one of saidvalves and to close the other of said valves, means to move said. lever,a pair of check. valves positioned in said. ducts and operable todeterminethe pres-'' sure of fluid discharging therethrough, a pair oibleed orifices opening from. said ducts into said: bleed. passageway,and said bleed orifices being operable to permit discharge of fluid atpressures below that at which said check valves are opened.

4. A control device comprising a casing enclosing a chamber, a fluidinlet passageway to said chamber, a pair of outlet passageways and ableed passageway in said casing, a pair of ducts leading from saidchamber to said outlet passageways, a pair of valves for controllingfluid flow through said ducts, a rockable lever operatively connected tosaid valves and operable upon rocking movement to open one of saidvalves and to close the other of said valves, means operable uponpredetermined movement to move said lever with a snap action, means tohold said lever at its limit of movement until said operating means hasmoved through substantially said predetermined movement, a pair of checkvalves positioned in said ducts and operable to determine the pressureof fluid discharging therethrough, a pair of bleed orifices opening fromsaid ducts into said bleed passageway and said bleed orifices beingoperable to permit discharge of fluid at pressures below that at whichsaid check valves are opened.

5. A control device comprising a casing enclosing a chamber, a fluidinlet passageway to said chamber, a pair of outlet passageways and ableed passageway in said casing, a pair of ducts leading from saidchamber to said outlet passageways, a pair of valves for controllingfluid flow through said ducts, a rockable lever operatively connected tosaid valves and operable upon rocking movement to open one of saidvalves and to close the other of said valves, means operable upon predetermined movement to move said lever with a snap action, a frictionspring operable to hold said lever at its limit of movement until saidoperating means has moved through substantially said predeterminedmovement, a pair of check valves positioned in said ducts and operableto determine the pressure of fluid discharging there through, a pair ofbleed orifices opening from said ducts into said bleed passageway andsaid bleed orifices being operable to permit discharge of fluid atpressures below that at which said check valves are opened.

6. A control device comprising a casing enclosing a chamber, a fluidinlet passageway to said chamber, a pair of outlet passageways and ableed passageway in said casing, a pair of ducts leading from saidchamber to said outlet passageways, a pair of valves for controllingfluid flow through said ducts, a rockable lever operatively connected tosaid valves and operable upon rocking movement to open one of saidvalves and to close the other of said valves, a bifurcated projectionextending laterally from said lever in a plane substantially normal tothe axis of the levers fulcrum, a second lever movabl between and engageable with the prongs of said bifurcated projection and operable torock said first-named lever, means operable upon predetermined movementof said second lever to cause th same to move with a snap action therebyto rock said first-named lever with a snap action, a friction springoperable to hold said first-named lever at its limit of movementuntilsaid second lever has moved the distance between the prongs of saidbifurcated projection, a pair of check valves positioned in said ductsand operable to determine the pressure of fluid dischargingtherethrough, a pair of bleed orifices opening from said ducts into saidbleed passageway and said bleed orifices being operable to permitdischarge of fluid at pressures below that at which said check valvesare opened.

7. A control device comprising a casing enclos ing a chamber, a fluidinlet passageway to said chamber, a pair of outlet passageways and ableed passageway in said casing, a pair of ducts leadin from saidchamber to said outlet passageways, a pair of valves for controllingfluid flow through said ducts, a rockable lever operatively connected tosaid valves and operable upon rocking movement to open one of saidvalves and to close the other of said valves, a bifurcated projectionextending laterally from said lever in a plane substantially normal tothe axis of the levers fulcrum, a second lever movable between andengageable with the prongs of said bifurcated projection and operable torock said first-named lever; a third lever, a member pivoted betweensaid second and third levers, a spring operatively connected to saidthird lever, said pivoted member being held compressively biased betweensaid secondand third levers and operable to transmit a biasing thrust tosaid second lever; said spring,

said third lever, and said pivoted member being operable upon movementof said second lever to an overcenter position to move said second leverthrough the remainder of its movement with a snap action thereby to rocksaid first-named lever with a snap action, a friction spring operableto. hold said first-named lever at its limit of move-- ment until saidsecond lever has moved the distance between the prongs of saidbifurcated projection, a pair of check valves positioned in said ductsand operable to determine the pressure of fluid dischargingtherethrough, a pair of bleed orifices opening from said ducts into saidbleed passageway and said bleed orifices being operable to permitdischarge of fluid at pressures below that at which said check valvesare opened.

8. A control device comprising a casing enclosng a liquid receivingchamber and having an inlet and an outlet, a valve for controllingliquid flow through said outlet, means to open and close said valve, anauxiliary bleed passageway in said casing; a diaphragm type check valvecomprising a cylindrical cavity and a sliding piston theren, a flexibleresilient diaphragm closing said cavity, aspring urging said pistonagainst said diaphragm, an annular cavity on the side of said diaphragmopposite said piston, a transverse passageway opening at one end intosaid annular cavity and at the other having a restricted openmg intosaid bleed passageway and having in its central portion an openingcommunicating with said outlet, an outlet passageway, a secondtransverse passageway opening into said outlet passageway at one end andthrough the central portion of said annulus against said dipahragm atthe other end, and said check valve being operable to determine thepressure of liquid discharging from said outlet.

EARNEST J. DILLMAN.

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